Loosing stack values on postback?

I believe I loose any stack values on postback.  I am hiding and showign panels and every time I do this, I loose my stack objects.

For example, in my code-behind I have something like this:

 

This first called:

        public void btnNewUser_NextStep_OnClick(object sender, EventArgs e)
        {
            // Hide/Disable logic
            NewUser.pnlNewUserHeader1.Enabled = false;
            NewUser.pnlNewUserContent1.Visible = false;
            this.pnlNewUserButtons.Visible = false;

            // Show logic
            SelectApplications.pnlSelectApplicationsHeader1.Enabled = true;
            SelectApplications.pnlSelectApplicationsContent1.Visible = true;
            Utility.IncrementStack(currentStep, 1);
        }

Then this is called when the user clicks on a button in the next panel and my stack values are lost here so the if statement always sees 0 for the stack value:

        private void btnSelectApplications_PreviousStep_OnClick1(object sender, EventArgs e)
        {
            // Hide/Disable logic
            SelectApplications.pnlSelectApplicationsHeader1.Enabled = false;
            SelectApplications.pnlSelectApplicationsContent1.Visible = false;
            Utility.DecrementStack(currentStep);

            // Show logic

            // TODO: This is just a hack for now until I finish the step logic 100%
            if (Utility.PeekStack(currentStep) == 1)
            {
                NewUser.pnlNewUserHeader1.Visible = true;
                NewUser.pnlNewUserContent1.Visible = true;
                this.pnlNewUserButtons.Visible = true;
            }
            else if (Utility.PeekStack(currentStep) == 2)
            {
                SearchUser.pnlExistingUserHeader1.Enabled = false;
                SearchUser.pnlExistingUserContent1.Visible = false;
            }
        }

 Do I need viewstate on or something or is it something elementary here?Start Free Trial